While I realize a quilt/bivy/minimal tarp is UL cutting edge, I'm somewhat old-fashioned in thinking why not just a larger tarp--my first double tarp followed Ray Jardines advice about 2 foot overhangs and besides being a bit heavy and requiring a large footprint, it did great. Then I went to a SpinTwinn and found I needed to drape a (Driduck) raincoat over my legs.
Now, since I think I can get my hands on some Nano (constructed like Epic only lighter), a MYOG bivy seems in order except why not just have a slightly bigger tarp and a quilt with a top made of Nano?
My quilts are Ray-Way kits with Polarquard 3-D and the Draftstopper works awesome on the double quilt. My solo quilt is made of much more breathable military surplus nylon, hence the desire for a bivy or a replacement.
Also, has anyone heard of moisture on an Epic or Nano bag freezing and cutting off all breathability?